Studies have shown that underwater adventures are popular and attractive to members of the public, and some theme parks and amusements parks have some form of underwater or aquatic observatory system in place.
A well-known system has a clear plastic tunnel passing through a large aquarium or oceanarium which is filled with coral and marine life. The tunnel has a moving walkway and patrons stand on the walkway and are transported through the aquarium.
Another popular known system also has a large aquarium or oceanarium and a semi-submersible vehicle is powered through the oceanarium with a low powered motor. The semi-submersible vehicle is powered through a propeller and requires stringent safety controls and highly trained operators to use the semi-submersible vehicle in a safe manner. The vehicles are difficult and clumsy to maneouver and loading and unloading of passengers is a slow process as the vehicle needs to be carefully powered into a mooring position, then needs to be moored (which can be time consuming), and passengers then need to embark and disembark in a manner to keep the correct buoyancy level of the vehicle. These semi-submersible vehicles suffer from a number of disadvantages including a low limit of passengers (usually about 20-25), singular viewing windows and ports required because of the high hull strength required.